It was nearly one thousand years ago that Opaline Arcana defeated Princess Twilight Sparkle and her friends. Her plan had succeeded, and the three ponykinds were split, their bonds broken. However, the ordeal left Opaline drained of her magic. If she revealed herself too soon, everything would have been for naught. She had a castle, but she couldn't leave.
While she still had her followers, there was one major issue: She is immortal, and they were not. Thus, she was eventually the only one left, and she required an assistant. Unfortunately, enchantments will only get a pony so far, and wild creatures aren't exactly reliable. While a young unicorn mare named Misty Brightdawn would come to her a few years before she would finally get her chance to return to the public eye, there were hundreds of years where very little happened.
However, about sixty of those years are an exception. Those were the years that she found herself with something she never expected.
A companion. A human companion.
Suggested by Wanderer312.
